Primary objectives of this proposal are: 1) To complete end point analysis for the Monitored Atherosclerosis Regression Study (MARS); and 2) To compare coronary versus carotid treatment effect relationships in MARS to coronary versus carotid treatment effect relationships in the Cholesterol Lowering Atherosclerosis Study (CLAD). MARS was a randomized, double-blind, placebo-controlled, angiographic trial comparing the effects of lipid lowering by lovastatin and diet with diet plus placebo in 270 subjects. The target study population consisted of males and females under 70 years of age with cholesterol levels from 200 to 295 mg/dL and coronary artery disease in two or more coronary artery segments. Follow-up coronary angiograms were performed two and four years post-randomization in 247 and 68 subjects, respectively; providing information on atherosclerosis regression/progression of coronary artery intrusive lesions. Carotid ultrasound images have been recorded at four month intervals for periods up to four years in 215 subjects providing information on atherosclerosis regression/progression of pre-intrusive (intima-media thickness) lesions in parallel with coronary artery intrusive lesions. Unique features of MARS include: 1) Simultaneous coronary angiography (evaluated both by quantitative coronary angiography (QCA) and panel-reading) and carotid ultrasonography in a cohort of over 200 subjects; 2) The opportunity to evaluate the largest lipoprotein an apolipoprotein data collected in an angiographic trial to date. This includes extensive VLDL, LDL, IDL, and HDL subclasses as well as LDL type pattern, lipoprotein particles and apolipoprotein (including AI, B, CIII, and E); and, 3) The opportunity to evaluate dietary effects on atherosclerosis regression/progression only in one other angiographic trail, CLAS. A unique feature of MARS and CLAS has shown a similar effect in CLAS-like men (non-smoking men with CABG) and women. Since carotid intima-media thickness, QCA, and global change score have been shown to be predictive of clinical coronary events, understanding the relationship between these atherosclerotic measures may be important in establishing carotid intima-media thickness measurements as a proxy measure for coronary atherosclerosis.